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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 | /* * INETPEER - A storage for permanent information about peers * * Authors: Andrey V. Savochkin <saw@msu.ru> */ #ifndef _NET_INETPEER_H #define _NET_INETPEER_H #include <linux/types.h> #include <linux/init.h> #include <linux/jiffies.h> #include <linux/spinlock.h> #include <linux/rtnetlink.h> #include <net/ipv6.h> #include <linux/atomic.h> struct inetpeer_addr_base { union { __be32 a4; __be32 a6[4]; }; }; struct inetpeer_addr { struct inetpeer_addr_base addr; __u16 family; }; struct inet_peer { /* group together avl_left,avl_right,v4daddr to speedup lookups */ struct inet_peer __rcu *avl_left, *avl_right; struct inetpeer_addr daddr; __u32 avl_height; u32 metrics[RTAX_MAX]; u32 rate_tokens; /* rate limiting for ICMP */ unsigned long rate_last; unsigned long pmtu_expires; u32 pmtu_orig; u32 pmtu_learned; struct inetpeer_addr_base redirect_learned; struct list_head gc_list; /* * Once inet_peer is queued for deletion (refcnt == -1), following fields * are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp * We can share memory with rcu_head to help keep inet_peer small. */ union { struct { atomic_t rid; /* Frag reception counter */ atomic_t ip_id_count; /* IP ID for the next packet */ __u32 tcp_ts; __u32 tcp_ts_stamp; }; struct rcu_head rcu; struct inet_peer *gc_next; }; /* following fields might be frequently dirtied */ __u32 dtime; /* the time of last use of not referenced entries */ atomic_t refcnt; }; void inet_initpeers(void) __init; #define INETPEER_METRICS_NEW (~(u32) 0) static inline bool inet_metrics_new(const struct inet_peer *p) { return p->metrics[RTAX_LOCK-1] == INETPEER_METRICS_NEW; } /* can be called with or without local BH being disabled */ struct inet_peer *inet_getpeer(const struct inetpeer_addr *daddr, int create); static inline struct inet_peer *inet_getpeer_v4(__be32 v4daddr, int create) { struct inetpeer_addr daddr; daddr.addr.a4 = v4daddr; daddr.family = AF_INET; return inet_getpeer(&daddr, create); } static inline struct inet_peer *inet_getpeer_v6(const struct in6_addr *v6daddr, int create) { struct inetpeer_addr daddr; *(struct in6_addr *)daddr.addr.a6 = *v6daddr; daddr.family = AF_INET6; return inet_getpeer(&daddr, create); } /* can be called from BH context or outside */ extern void inet_putpeer(struct inet_peer *p); extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout); extern void inetpeer_invalidate_tree(int family); /* * temporary check to make sure we dont access rid, ip_id_count, tcp_ts, * tcp_ts_stamp if no refcount is taken on inet_peer */ static inline void inet_peer_refcheck(const struct inet_peer *p) { WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0); } /* can be called with or without local BH being disabled */ static inline int inet_getid(struct inet_peer *p, int more) { int old, new; more++; inet_peer_refcheck(p); do { old = atomic_read(&p->ip_id_count); new = old + more; if (!new) new = 1; } while (atomic_cmpxchg(&p->ip_id_count, old, new) != old); return new; } #endif /* _NET_INETPEER_H */ |